This invention relates to rotary cutting tools for finishing bores in work pieces, and particularly to an inserted blade end mill. In end mills as well as larger diameter cylindrical mills, it is well known to use tapered blades inserted in sockets generally along the axis of rotation of the cylindrical cutter body. Longitudinal serrations on one side of the blades engage like serrations on sockets in the body to hold the blade from being thrown radially out of the body sockets under the forces of cutting. Such blades are quite satisfactory in large cylindrical bodys over three inches in diameter. But in the small diameters of approximately one half to three inches the sockets receiving the blades are so closely spaced that the remaining volume of the body between sockets is small and yielding. Consequently in small diameter end mills the blades tend to twist in their sockets and chatter, losing precision and greatly reducing their cutting efficiency. Multiple blade end mills under one inch in diameter are not feasible as previously made.
Accordingly it is the object of the present invention to provide practical, multiple inserted blade end mills in a diameter range of one half to three inches.